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Estimates creatinine clearance using the Cockcroft-Gault formula (Cockcroft DW, Gault MH, "Prediction of creatinine clearance from serum creatinine", Nephron, 1976): CrCl (mL/min) = ((140 - age) x weight (kg) x [0.85 if female]) / (72 x serum creatinine (mg/dL)). This is a widely-published, standard reference-range estimation formula, distinct from full eGFR/CKD-EPI equations (which do not use weight). For general reference and educational purposes only — not a medical diagnosis. Consult a doctor for actual kidney function assessment and drug dosing decisions.
How it works
Enter age, weight in kilograms, sex, and serum creatinine in mg/dL. The tool applies the Cockcroft-Gault formula directly.
- Enter age (years).
- Enter weight (kg).
- Enter sex.
- Enter serum creatinine (mg/dL).
- Click Calculate to see your results.
Examples
Age 60, weight 70 kg, male, creatinine 1.0 mg/dL
CrCl = ((140-60) x 70) / (72 x 1.0) = 5600 / 72 ≈ 77.8 mL/min.
Who should use it
- Reviewing a kidney function estimate alongside a doctor or pharmacist.
- Pharmacology and nephrology education about renal dosing.
Industry applications
- Clinical pharmacology and drug dosing reference
- Nephrology education
Advantages
- Long-established, widely cited, simple formula.
- Commonly referenced in drug dosing literature.
Limitations
- Less accurate than eGFR equations in some populations (e.g., obesity, extremes of muscle mass).
- Less reliable during rapidly changing (non-steady-state) kidney function.
Common mistakes to avoid
- Using an outdated or non-steady-state serum creatinine value (e.g., during acute kidney injury, when Cockcroft-Gault is less reliable).
- Using ideal or adjusted body weight without checking which weight convention is intended for the context.
Best practices
- Use actual body weight for a standard Cockcroft-Gault estimate unless a specific clinical protocol calls for adjusted or ideal body weight.
Tips
- Cockcroft-Gault remains the formula most drug dosing guidelines reference, even though CKD-EPI is now preferred for general kidney function staging.